Improved multiparametric MRI discrimination between low‐risk prostate cancer and benign tissues in a small cohort of 5α‐reductase inhibitor treated individuals as compared with an untreated cohort

Abstract

The study purpose was to determine whether 5α-reductase inhibitors (5-ARIs) affect the discrimination between low-grade prostate cancer (PCa) and benign tissues on mpMRI. Twenty men with biopsy-proven Gleason 3+3 PCa and 3T mpMRI were studied. Ten patients (Tx) were receiving 5-ARIs for at least a year at scan time. Ten untreated patients (Un) were matched to the treated cohort. For each subject two regions of interest (ROI) representing cancerous and benign tissues were drawn within the peripheral zone of each prostate, MR measures evaluated, and cancer contrast versus benign [Contrast=(MRTumor-MRHealthy)/MRHealthy] calculated. Decreased cancer contrast was noted on T2-weighted images: 0.4 (Un) versus 0.3 (Tx). However, for functional MR measures, a better separation of cancerous and benign tissues was observed in the treated group. Cancer contrast on high-b diffusion weighted images (DWI) was 0.61 (Un) vs. 0.99 (Tx). Logistic regression analysis yielded higher AUC (area under the curve) values for distinguishing cancerous from benign regions in treated subjects on high-b DWI [0.71 (Un), 0.94 (Tx)], maximal enhancement slope [0.95 (Un), 1 (Tx)], peak enhancement [0.84 (Un), 0.93 (Tx)], washout slope [0.78 (Un), 0.99 (Tx)], Ktrans [0.9 (Un), 1 (Tx)], and combined measures [0.86 (Un), 0.99 (Tx)]. Coefficients of variation for MR measures were lower in benign and cancerous tissues in the treated group compared to the untreated group. This study's results suggest an increase in homogeneity of benign and malignant peripheral zone prostatic tissues with 5-ARI exposure, observed as reduced variability of MR measures after treatment. Cancer discrimination was lower with T2-weighted imaging, but was higher with functional MR measures in a 5-ARI-treated cohort compared to controls.

Prostate cancer detection using quantitative T2 and T2‐weighted imaging: The effects of 5‐alpha‐reductase inhibitors in men on active surveillance

“…Starobinets et al 29 reported no significant differences in contrast on T 2 -WI between untreated and treated men. Similarly, we did not find any difference between the two arms, both at baseline and after 6 months of exposure to dutasteride.…”

“…9 Cancerous tissue consists of highly compacted cells, and this results in a decrease in T 2 signal. 22 Although several recent studies have also evaluated the utility of quantitative T 2 imaging in prostate cancer, 12,[23][24][25][26][27][28][29] quantitative in vivo T 2 mapping is still a challenge due to the long scan duration, and therefore this approach is not routinely performed during a standard prostate mpMRI scan.…”

The effect of 5 alpha-reductase inhibitor therapy on prostate cancer detection in the era of multi-parametric magnetic resonance imaging

“…Currently, with the wide use of mpMRI, several studies have investigated the effect of 5-ARIs on mpMRI in PCa patients 10–13 . In a randomized, double-blind, placebo-controlled trial involving a total of 42 patients (MAPPED [MRI in Primary Prostate cancer after Exposure to Dutasteride] trial), Moore et al .…”

“…10 reported that dutasteride was associated with a significant (48%) reduction in PCa volume in T2-weighted imaging (T2WI) compared with placebo (P < 0.0001). However, other studies investigating the changes in quantitative parameters of PCa and noncancerous lesions have shown conflicting results 11–13 . Giganti et al .…”

Imaging and clinical features of giant multilocular prostatic cystadenoma

“…On DWI, the SI indicates diffusion restriction in the abscess, which is different from appearance of GMPC. [ 17 ] MRI can also be used to discriminate malignancies such as sarcoma and cystadenocarcinoma. These malignancies may present multiple cystic mass but more solid component than GMPC, markedly high SI on DWI and low SI on ADC are important for differential diagnosis.…”